Provider records sourced from NPPES (CMS National Plan & Provider Enumeration System). Data current as of August 10, 2026.

Harold S. Nelson, MD

Individual provider Clinical & Laboratory Immunology (Internal Medicine) Physician · NPI 1104916873

Harold S. Nelson, MD is a Clinical & Laboratory Immunology (Internal Medicine) Physician in Denver, Colorado. Licensed in Colorado. Registered with an NPI since 2006.

Licensed in
CO
In the registry since
2006
Specialties on file
2
What do these letters mean?
MD — Doctor of Medicine
A physician who completed allopathic medical school.

See every abbreviation used in this directory →

Practice location Address checks out

1400 Jackson St
Denver, CO 80206-2761
Phone: (303) 388-4461
Fax: (303) 270-2174
Show map & directions

Pin is approximate — placed at the ZIP-code centre, not the exact door.

Specialties & licences

Allergy & Immunology Physician (primary) Taxonomy 207K00000X · Licence 18391 (CO)
Clinical & Laboratory Immunology (Internal Medicine) Physician Taxonomy 207RI0001X · Licence 18391 (CO)

Record details

NPI number1104916873
Entity typeIndividual (Type 1)
GenderMale
Credentials MD
Sole proprietorNo
NPI enumeratedOctober 13, 2006
Last updated in NPPESNovember 12, 2020
Certification dateNovember 12, 2020